Methods consistent with the present disclosure relate to a semiconductor memory, and more particularly, to an operation method of a nonvolatile memory system.
A semiconductor memory is implemented by using semiconductor such as silicon (Si), germanium (Ge), gallium arsenide (GaAs), indium phosphide (InP), or the like. A semiconductor memory device is roughly divided into a volatile memory device and a nonvolatile memory device.
A volatile memory device refers to a memory device which loses data stored therein at power-off. The volatile memory device includes a static random access memory (SRAM), a dynamic ram (DRAM), a synchronous DRAM or the like. A nonvolatile memory device refers to a memory device which retains data stored therein even at power-off. The nonvolatile memory device includes a read only memory (ROM), a programmable ROM (PROM), an electrically programmable ROM (EPROM), an electrically erasable and programmable ROM (EEPROM), a flash memory device, a phase-change RAM (PRAM), a magnetic RAM (MRAM), a resistive RAM (RRAM), a ferroelectric RAM (FRAM), or the like.
In particular, a flash memory device is a high-capacity storage device and is widely used in various fields. The flash memory device is a nonvolatile memory device but will lose data stored therein due to various factors such as temperature, read disturbance, program disturbance, and charge loss. Accordingly, there are being developed various methods for securing integrity of data stored in a flash memory device.